The optical mouse uses a very small light emitting diode more commonly referred to as an LED which is red in color. This LED bounces light off of a mouse pad or desk surface onto a CMOS (Complimentary Metal Oxide Semiconductor) sensor. The CMOS sensor sends each image that is reflected back to a DSP (Digital Signal Processor) for analysis.Using the thousands of images that the CMOS sends to the DSP for analysis, the DSP is able to detect both patterns and images and can determine if the mouse has moved, at what distance it has moved and at what speed. It is able to determine coordinates which are then sent to the computer that the mouse is hooked up to.

Can I install a USB mouse on an Acer Aspire One running the factory installed Windows XP?

All you need to do is connect the USB mouse and it will start to work, this also goes for USB keyboards and other USB input devices.

The operating system of my PC is Linux, then could I directly use this USB 3D optical mouse?

Yes. Almost all basic input devices (keyboards, mice etc) work straight away in linux without doing anything. Just plug and play. This is the same as Microsoft Windows.